Jack is a twenty-nine-year-old wealthy bachelor who lives a double life. In London, he goes by the alias "Ernest" to enjoy a dissolute lifestyle, while in the country, he acts as a sober, responsible guardian to his young ward. Discovered as an infant in a handbag at Victoria Station, his lack of known family origins presents a major obstacle to his social and romantic ambitions.

Algernon is a glib, provocative bachelor belonging to the landed aristocracy, though he constantly struggles with his finances. He delights in flouting social conventions and uses a fictional sick friend named "Bunbury" to escape unwanted obligations. He views romance as an amusing game rather than a serious, transaction-based commitment.

Lady Bracknell is an imperious, sharp-tongued aristocrat who rigidly enforces Victorian social rules. She acts as a fierce gatekeeper to high society, interrogating suitors to ensure they meet her strict standards of wealth and lineage. She dismisses modern sympathies and views marriage as a purely transactional arrangement intended to preserve class status.

Gwendolen is Lady Bracknell's daughter and a wealthy, fashionable young woman. She is headstrong but operates under the superficial idealism of her era, firmly believing she is destined to marry a man named Ernest. She is devoted to Jack solely based on her assumption about his name.

Cecily is Jack's eighteen-year-old ward who lives entirely in the country. Bored by her studies and isolated from London society, she maintains a vivid fantasy life, going so far as to write out a completely fictional courtship in her diary. She harbors a deep fascination with Jack's imaginary, wicked brother.

Miss Prism is the well-meaning but largely unqualified governess employed at Jack's country estate. She struggles to keep her student focused and frequently misunderstands academic and social references. She carries quiet romantic hopes regarding the local clergyman and mentions a past attempt at writing a three-volume novel.

Dr. Chasuble is the local church canon who tends to the parish near Jack's estate. He is a scholarly, slightly pompous man who believes his standard sermons can be applied to any situation, from christenings to agricultural crises. He returns Miss Prism's affections but feels constrained by his clerical position.

Lane is Algernon's butler in London. He maintains a perfectly deadpan demeanor while actively enabling his employer's lies and deceptions, particularly when dealing with Lady Bracknell. He provides a working-class contrast to Algernon's aristocratic frivolity.

Merriman is the dutiful butler at Jack's country home. He manages the practical logistics of the household and impassively observes the escalating romantic chaos among the upper-class characters, including setting up tea services that turn into battlegrounds.